847 research outputs found
Counting Cubic Extensions with given Quadratic Resolvent
Given a number field and a quadratic extension , we give an explicit
asymptotic formula for the number of isomorphism classes of cubic extensions of
whose Galois closure contains as quadratic subextension, ordered by
the norm of their relative discriminant ideal. The main tool is Kummer theory.
We also study in detail the error term of the asymptotics and show that it is
, for an explicit .Comment: 19 page
A dissociation between real and simulated movements in Parkinson's disease
Subcortical lesions have been simultaneously implicated in both real and simulated movement deficits. However, the analysis of the simulated opposition axis in precision grasping reveals that, in individuals with idiopathic bilateral Parkinson's disease motor imagery is impaired and that execution of overt movements is spared. This constitutes the first lesion observation congruent with the anatomical and functional dichotomy between real and simulated movements seen in experimental studies. These results underline the modality-specific nature of motor imagery and show that subcortical damage differentially impacts on motor activity
Finite hypergeometric functions
Finite hypergeometric functions are complex valued functions on finite fields
which are the analogue of the classical analytic hypergeometric functions. From
the work of N.M.Katz it follows that their values are traces of Frobenius on
certain l-adic sheafs. More concretely, in many instances their values can be
used to give formulas for pointcounts of F_q-rational points on certain
varieties. In this paper we work out the case of one-variable functions whose
monodromy in the analytic case can be defined over the rational integers.Comment: 26 pages, 2 figure
Ap\'ery Acceleration of Continued Fractions
We explain in detail how to accelerate continued fractions (for constants as
well as for functions) using the method used by R.~Ap\'ery in his proof of the
irrationality of . We show in particular that this can be applied to
a large number of continued fractions which can be found in the literature,
thus providing a large number of new continued fractions. As examples, we give
a new continued fraction for and for , as well as a simple
proof of one due to Ramanujan
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